The invention relates particularly to retrieving information from a database with the help of search criteria transmitted by telephone, but the method and the solution, according to the invention, can also be used in other telecommunication connections.
Normally, the subscriber A gives orally the search criteria by means of which the subscriber B manually retrieves the information. In this case, the retrieval of information is slow. In addition, unnecessary, overlapping work is being done because, in practice, the search criteria are given twice. The degree of error is also high, and incorrect information, retrieved on the basis of incorrectly given search criteria, may be handled without anyone noticing the matter at the time.
In the solution of U.S. Pat. No. 5,109,399, information is retrieved from a map database using an automatically received telephone number of a fixed, wired network as the search criteria. The problem of the presented solution is inadequate safety, e.g., when retrieving confidential information, because anyone who calls with the subscriber device of the subscriber A is capable of retrieving, from the database, the information relating to the telephone number. Thus, it is impossible to retrieve any confidential information. Another problem is dependence on the device and the location, because the subscriber A can only retrieve the correct information from the database when calling from a subscriber device located in a specific place and connected to a fixed network.
A similar solution is described in U.S. Pat. No. 5,077,788 in which location information about a calling station is searched from a computer memory based on the number of the calling station.
Publication WO 95/24107 discloses a cellular telephone fraud control system, in which a switch of a mobile telephone system receives both the CLI (Caller Line Identification) and a Caller Authentication Number (CAN) input by the user of the mobile telephone for verifying an authorized user. When an authorized user is verified a call from the mobile telephone is connected.